Packing-bingr and piston



.I. T. WILSON.

PACKING RING AND PISTON. APPLICATION FILED APR. 21. m

3mm efalifl I PVT/son UNITED STATES PATENT OFFICE.

JO HN WILSON, OF ALA MEDA, CALIFORNIA.

1 To allwhom it may concern:

Be it known that 1, JOHN T. W1 soN, a citizen of the United States,residing at Alameda, in the county of. Alameda and State of California,have invented certain new and useful Improvements in Packing- Rings andPistons; and I do hereby declare the following to be a full, clear, andexact description of the invention, sueh as will enable others skilledin theart to which it appertains to make and use the same.

an integral cylindrical casting provided with circumferential rooves-inits exterior surfaceto receive'pac ing rings which frictionall bearagainst the interior surface of to great pressurepby the eneratedenergy.

the cy inder to form tight joints therewith during all periods of thereciprocating motionsof the piston. j a H The front end of the pistonand the packing rings which project slightly beyond the exterior surfaceof the piston are subjected of the ex losive charge. he packing ringsnecessari y are of small cross sectional area and cut a art so'they canbe sprung over the end 0 the pistoninto the grooves. Be-

ing ofsmall dimensions, they soon wear out and the piston bodythenfrictionally en gages the interior surface of the cylinder and Wearsaway the metal of the cylinder and o ens a passageway for the gasesgenerate by the explosion. Also the ends of the rings frequently breakand become displaced so the gases can pass. Under the same conditionswhen explosive charges are drawn into the explosion chamber, a vacu umbeing formed therein, lubricating oil from the crank chamber is suckedpast the packing rings into the explosion chamber, where it becomescarbonized and fouls the cylinder and piston.

These conditions obviously impair the efiicienc ofthe engine, and theremedy therefor oesnot consist simply in using wider packing rings, forthe wider the ring, the greater the pressure beneath it ,andrthe greaterthe friction between the ring and the cylinder.

The object of the present invention is to cure these imperfections byproviding a compound or double packing ring, of a shape conforming tothe shape of the groove in the piston, and presenting a relatively largearea of exterior wearing surface and Specification of Letters ratent.

A gas engine piston usually consists of.

PACKING-BING- AND PISTON.

Patented Mar. 8, 1921.

Application filed April 21, 1919. Serial No. 291,434.

a muchless area of surface at the interior to be acted upon b thepressure of the explo s1ve gases and t a pressure of the explosivelubricatin oil, to pass beneath the entire under surface of the packing.

The invention consists in a compound or double cut resilient expansiblepacking ring and a piston having a groove ofa sha e in conformity withthe shape of the ringw ereby the results above set forth are obtained.

Further, the invention consists incertain novelties of construction andrelative ar rangements, as herein set forth, ofthe ring, the groove inthe pistonadapted to receive 1tohe ring, and the crank and explosionchamers.

The accompanying drawing illustrates an example of the embodiment of theinvention constructed and the parts combined accord ing to the best ofthe several modes of procedure I have so far devised for the attainmentof the ends set forth.

Figure 1 is a vertical section in elevation of a gas engine piston andcylinder showing my invention, several packing rings being in section.Fig. 2 is a "side view in elevation of the spring and pressure rinshowing the ends slightly separated and t eprojecting flange to form abottom lap plate.

Fig. 3 is a cross section. of Fig. 2 on line 33.

Fig. 4 is a side View in elevation of the Wearing ring, the endsbeingslightly spaced apart.

Fig. 5 is a section of 'Fig. 4 on line 5-5.

Fig. 6 is a top plan view of the assembled rings as they appear whensprung together and in the cylinder, the lap joint being clearlyindicated, g I

Fig. 7 is asection of Fig.6 on line 7-7.

Fig. 8 illustrates the positionofthe packing ring in the groove when thecharge is being drawn into the explosion chamber.

Fig. 9 illustrates the position of the ring The last two figures aresomewhat out of proportion to more clearly illustrate the positions ofthe rings.

Referring to the figures, the letter A designates a solid piston of wellknown general shape and construction. exclusive of the shape of thegrooves in its exterior surface. The lines B-B and shading linesrepresent part of the interior circular surface of the engine cylinderpresenting a smooth surface throughout, and part of the metal. of thecylinder. C is the end of the piston forming the movable inclosingboundary of the explosion chamber D, and E is the end of the pistonfacing the inclosed crank chamber space F which contains a heavy lubricating oil or other lubricant. G designates the grooves in theexterior surface of the metallic body of the piston. R are the compoundor double packing rin s.

Referring to a single combined groove and ring, it will be noted thateach is adapted to the shape of the other. The outer part of the groove1 is of the same width throughout the circumference of the piston. Itsdepth at 2 adjacent the end of the piston next to the explosion chamberis greater than its depth at 3 adjacent the crank chamber end of thepiston. In other words, the groove is of a general L shape and thevertical surfaces defining the same are plain to match the surfaces atthe sides of the packing ring.

The ring R is shaped to loosely fit the groove, its exterior portionbeing wider than its interior portion, and of a general L shape in crosssection. The part 4 may be called a flange and in the groove it isremote from the explosion chamber and faces the crank chamber. The ringmay project slightly from the groove to engage the interior surface ofthe cylinder and there should be a slight space as indicated between theside and bottom surfaces and the metal surfaces defining the groove sothe ring can float longitudinally relative to the axis of the piston andalso at right angles thereto so as to frictionally engage the interiorsurface of the cylinder throughout.

The ring is comprised of two assembled resilient cut spring rings a andb, the spring and pressure ring a being under greater tension when therings are united and in the cylinder than the bearing ring b.

Ring a has a flange 0 which is cut at the points d and e to form abottom lap plate 7. as shown. A dowel pin 9 is located. in the flange.Ring 7) in this instance has a flange h and is cut on a straight line.

When assembled, the wearing ring Z) isin contact with the flange c ofthe ring a, as shown by Fig. 7, and the ends located at opposite sidesof the dowel pin 7 so one ring cannot shift relative to the other. Thejoint is clearly indicated by full and dotted lines in Fig. 6. Thespring ring holds the wearing ring in contact with the inner surface ofthe cylinder under all conditions of service, as is obvious.

It should be noted here that in gas engine practice, unlike that whensteam is the motive power, the packing ring must loosely fit the groovein the piston so that when the ring and groove become fouled by theproducts of incomplete combustion of the charge, which is always thecase more or less, the ring will not stick in the groove. That is, thering should have some slight side play within the groove so it will notpack and be prevented from expanding against the interior surface of thecylinder.

The ring in the operation of the engine is subjected to three varyingpressures.

First, when the charge is drawn in, a vacuum being formed in theexplosion chamber, air and oil at atmospheric pressure, at 15 pounds tothe square inch or less, pass to the entire under surface of the ringwhich does not excessively force the ring against the interior surfaceof the cylinder, but sufficiently to prevent the passage of oil beyondthe ring to the explosion chamber. The pressure against the entire undersurface of the ring is not sufficient to cause excessive friction andwear of the ring, so a quite wide wearing ring may be employed underthese conditions. The ring occupies the position shown in Fig. 8, thesurfaces of the ring and groove at m being in frictional contact so asto form a tight joint against the passage of air or oil.

Secondly, when the charge is being compressed, the ring shifts to theposition shown in Fig. 9, the mixture under compression passing to thespace 0 beneath only part of the under surface of the ring, the surfacesof the ring and groove at s forming a tight joint so the pressure cannotreach the under surface of the ring flange.

Thirdly, when the explosion of the charge is taking place the ring undervery great pressure maintains its position shown in Fig. 9 and excludespressure from the under surface of the flange of the ring.

Under the last two conditions enumerated the pressure under part of thering is sulficient to force the ring into frictional contact with theinterior surface of the cylinder and maintain a tight joint therewith soa much wider ring can be used without occasioning excessive wear thereofor wear of the interior surface of the cylinder.

It is clear that a piston and ring combined and o crating as hereindescribed attain very esirable results. A relatively large bearingsurface is secured so the ring will wear much longer than a narrowerring which is liable to break, and the ring is not forced against theinterior surface of the cylinder by great or excessive pressure duringthe explosion of the charge, for the greatest pressure, due to theexplosion of the charge, is excluded from part of the under surface ofthe ring. It is also clear that oil from the crank chamber cannot passpiston than at the bottom, the greatest depth of said groove beingadjacent the explosion chamber, of a double cut resilient expansibleflanged packing ring of a shape in cross section matching and looselyfitting the roove and its entire exterior surface frictionally engagingthe interior surface of the cylinder, the rings comprising the doublering being arranged so as to exclude explosion and charge compressionpressure from the flanged portion of the ring.

2. The combination with a piston having acircumferential groove wideradjacent the exterior surface of the piston than at the bottom, thegreatest depth of said groove being adjacent the explosion chamber, of atwo-part cut resilient expansible packing ring of a shape in crosssection matching and loosely fitting the groove, said rings forming aoint closing the open s ace otherwise present between the ends 0 therings and adapted to allow the ring to be sprung over the end of thepiston and seat 1n the groove In testimony whereof I afiix my si nature.

JOHN T. wnfsoN.

